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wiring ceramic lamps/strain relief necessary

updated sat 31 may 97


Jeff Lawrence on thu 8 may 97

Cindy said:
>Voila. Yep, that's it. Oh . . . and don't plug it in until you're
>completely finished, but you knew that.
Cindy Strnad has a good attitude toward electricity -- it's manageable if
you bring some common sense to bear. I'd like to add a couple of caveats to
her comments, which flow from four years of dealing with UL on my lighting

One important thing is "strain relief." For portable lamps, UL mandates a
strain relief that can withstand 35lb. This can either be a knot in the wire
or a crimp-on metal clamp, that resists the casual tug on the wire. The idea
is to avoid tear live electrified wires loose from contact screws and
electrocuting someone. Therefore, put the clamp or knot inside the lamp
body so that pulling the wire puts strain on the knot or clamp instead of
contact screws.

Another thing to consider is shielding and grounding live metal. Depending
on the sockets you get, contact screws may be accessible to the casual hand.
Bad news for the curious! Make sure your sockets provide some shielding for
live wires, or provide your own with whatever. Electrical tape over the
screws if nothing else. Also, UL says that any metal that can be touched
should be grounded.

Both these items are doable with some thought and shopping for proper
components. Please implement them if you want to sell table lamps.
Electrocuting your customers will have a bad effect on your repeat business.

Jeff Lawrence
Sun Dagger Design
ph/fax 505-753-5913